An ion milling device is a device for polishing a surface or cross section of a metal, glass, ceramic, or the like by irradiating the surface or cross section with an argon ion beam, and is favorable as a pre-processing device for observation of a surface or cross section of a sample using an electron microscope.
In the conventional cross-sectional observation of a sample using an electron microscope, a vicinity of a part to be observed is first cut by using a diamond cutter, a jigsaw, or the like, for example. Then, after the cut surface is mechanically polished, the sample is placed on a sample table for an electron microscope and the image of the cut surface is observed.
The mechanical polishing has a problem that, when a soft sample such as of a polymer material or aluminum is polished, the surface to be observed is crushed or deeply scratched by particles of an abrasive compound. Moreover, the mechanical polishing also has problems that it is difficult to polish a hard sample such as of glass or a ceramic and that it is extremely difficult to perform cross-section processing on a composite material in which a soft material and a hard material are stacked.
On the other hand, ion milling has advantageous effects of being capable of processing a soft sample without crushing the profile of the surface, of being capable of polishing a hard sample and a composite material, and of being capable of easily obtaining a cross section in a mirror state.
Patent Literature 1 describes a sample fabricating device including: ion beam irradiating means, disposed in a vacuum chamber, for irradiating a sample with an ion beam; a tilt stage disposed in the vacuum chamber and having a tilt axis in a direction substantially perpendicular to the ion beam; a sample holder, disposed on the tilt stage, for holding the sample; and a shielding member, located on the tilt stage, for blocking part of the ion beam for irradiating the sample, the sample fabricating device being configured to process a sample with the ion beam while changing a tilt angle of the tilt stage.